The use of dental prostheses to replace missing or damaged teeth is commonplace. Typically, artificial roots, or implants, are implanted into the bone of the patient's jaw and are used to provide structural support to an intermediate abutment. One or more artificial replacement teeth or crowns are then fastened to the abutment typically by cement or screws.
FIGS. 1A to 1D illustrate partial cross-sectional side views of one example of a typical crown being implanted within a mouth of a patient. Depending upon the number of teeth to be replaced, one or more holes may be bored within the bone of the jaw. As shown in FIG. 1A, a portion of the patient's gums or gingiva 14 may be cut open to expose the underlying bone 10, e.g., maxilla or mandible, into which a drill bit 16 may be used to bore open a hole 12. An anchoring dental implant 18, optionally threaded, may be implanted within the hole 12 and covered by gingiva 14 to allow for healing and for the implant 18 to take hold within the bone 10, as shown in FIG. 1B.
Once the implant 18 has been desirably positioned within bone 10, an abutment assembly 20 may be securely attached to implant 18, e.g., by a threaded pin 22 coupling to an implant receiving well 26 defined within implant 18 such that abutment 24, which defines a portion projecting through gingiva 14, as shown in FIG. 1C. With abutment assembly 20 secured to implant 18, an oral appliance 28, such as a crown, which defines an appliance opening 30 may be secured upon abutment 24 by utilizing a number of securement mechanisms, such as cement or a fastener such as a screw. Other securement mechanisms have also included interference fitting, such as with a cross-bar or O-ring type attachment, magnets, etc.
Because the implant, abutment, and oral appliance are subjected to high compressive and shear forces, initial positioning of the oral appliance is important not only to provide adequate structural support but also to ensure patient comfort. However, while utilizing cement to attach the oral appliance to the abutment initially allows for aligning the oral appliance more naturally with the dentition of the patient, the tolerance for mistakes is low once the cement has set because of the difficulty and expense in removing a cemented oral appliance from the abutment. In addition, dental professionals often apply too much cement to the area surrounding the abutment. Such excess cement has been shown in studies to be associated with high rates of peri-implant disease in patients receiving certain oral appliances. See Wilson, Thomas G. The positive relationship between excess cement and peri-implant disease: a prospective clinical endoscopic study. Journal of Periodontology 2009: 80: 1388-1392.
Screw-type retention devices may also provide for good securement of the oral appliance to the abutment, but occlusal contact within the patient dentition is often misaligned resulting in a variety of complications. For instance, misaligned crowns result in a compromised occlusal table which in turn may lead to chipping of the crowns as well as poor aesthetic appearance of the patient's dentition.
Accordingly, there exists a need for methods and devices which can effectively and efficiently facilitate not only the retention of oral appliances, such as crowns, bridges, or dentures, along the dentition of a patient but also the removal and/or repositioning of such oral appliances without causing unnecessary damage to the oral appliance.